Speaking of Ozzy and Sharon's reaction to his diagnosis, he told US Weekly: "They're supportive, but I've learned to not really tell them what's going on because they worry so much.

"I asked my mom why and she's like, 'Imagine if something happened to Pearl'. Then I understood. My dad's got a neurological issue himself, and at one point they thought he had MS. He's like, 'You'll figure it out'.

"I don't know how long things will be as good as they are. It can become a progressive disease, though, and if it gets bad, the decline can be rapid.

"That's why I don't want to say my diagnosis was a good thing, but it has definitely put things into perspective. I'm not going to craft my life according to the disease."